From mboxrd@z Thu Jan  1 00:00:00 1970
From: Keir Fraser <keir.fraser@eu.citrix.com>
Subject: Re: Re: IRQs, move_in_progress, -EBUSY &c
Date: Wed, 11 Aug 2010 19:18:41 +0100
Message-ID: <C888A811.1D715%keir.fraser@eu.citrix.com>
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To: George Dunlap <George.Dunlap@eu.citrix.com>
Cc: Fitzhardinge <jeremy@goop.org>, "xen-devel@lists.xensource.com" <xen-devel@lists.xensource.com>, Jeremy, "Zhang, Xiantao" <xiantao.zhang@intel.com>, Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
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On 11/08/2010 18:49, "George Dunlap" <George.Dunlap@eu.citrix.com> wrote:

> Seems to work about 50/50.
>=20
> Attached is a log of a successful boot (exile.008.log), and a failed
> boot (exile.009.log).  Suspicious things about the failed case:  the
> usb code starts to initialize before the SATA code finishes
> initializing, and complains that "Controller is probably using the
> wrong IRQ".

Cc'ing Xiantao Zhang, who submitted the per-CPU IDT patches. Perhaps he has
some ideas how to fix this. The only other simple thing I can think to try
is to modify my patch so that it loops in the hypervisor. Something like:
 do{ ret =3D mp_register_gsi(...}; } while (ret =3D=3D -EBUSY);
Since the condition being EBUSYed on is cleared in hardirq context, that
should be safe.

Apart from that, it is possible that greater surgery is neede don the
per-CPU IDT and IRQ migration logic, and I think we need Xiantao's help for
that.

 -- Keir

> Keir: the machine in question (as you may have guessed) is exile; let
> me know if you want to grab it and use it directly.
>=20
>  -George
>=20
> On Wed, Aug 11, 2010 at 4:59 PM, Keir Fraser <keir.fraser@eu.citrix.com>
> wrote:
>> On 11/08/2010 15:56, "George Dunlap" <George.Dunlap@eu.citrix.com> wrote=
:
>>=20
>>> However, it seems that moving IRQs is not handled properly. =A0Either
>>> the pvops kernel should retry if it gets an -EBUSY, or the hypercall
>>> should not fail, but wait until it can return success.
>>=20
>> Can you try the attached patch?
>>=20
>> =A0Thanks,
>> =A0Keir
>>=20
>>> I discovered all this by adding debug statements to the IRQ path; the
>>> patch is attached, if anyone else wants to use it.
>>>=20
>>> =A0-George
>>=20
>>=20
>> _______________________________________________
>> Xen-devel mailing list
>> Xen-devel@lists.xensource.com
>> http://lists.xensource.com/xen-devel
>>=20
>>=20